Socrates thinks that the person who is aware of his ignorance is wiser than the person who thinks he knows something when he doesn't. but if neither person knows anything, how can one be wiser than the other? what kind of wisdom could socrates be referring to here?

Socrates believes that the person who is aware of her or his ignorance possesses a common sense regarding it or a lack of hubris regarding his knowledge. Hubris is a term commonly used in ancient Greek to describe a person’s excessive pride in oneself.  

He or she acknowledges her or his shortcomings regarding the knowledge that she or he is lacking, which makes him a wiser individual compared to the person who thinks that he knows something when he doesn’t.  

which sentences ? that question is incomplete

elastic potential energy